氨基修饰增强的Fe/Cu-MOF对罗丹明B的光催化降解性能及相关机理

利用溶剂热合成法合成了氨基修饰的Fe/Cu-MOF-NH2,分别采用XRD、SEM、N2吸附-脱附、UV-vis、EA等检测方法进行了表征分析,并将其用于RhB的光催化降解,考察了 RhB的初始质量浓度、催化剂质量浓度和pH对光催化降解的影响.结果表明,氨基的引入显著提升了催化剂的可见光响应性能;在合成Fe/Cu-MO...     

碘掺杂TiO2可见光光催化性能研究

在低于100℃温度条件下,采用溶胶-凝胶法以钛酸正丁酯为钛源,碘酸钾为碘源,制备了I掺杂纳米TiO2催化剂(I-TiO2),运用X-射线衍射(XRD)、透射电镜(TEM)及X-射线光电子能谱(XPS)等对催化剂进行表征,结果表明,TiO2及I-TiO2催化剂均为锐钛矿,I吸附并包裹在TiO2表面或以间隙进入的形式存在,并未进入TiO2晶格。通过在可见光照射下(λ>420 nm)以罗丹明B(Rhodamine B,RhB)的光催化降解为探针反应研究了在不同条件下制备催化剂的催化性能,结果表明,掺杂比为nI:nTi=0.05∶1,焙烧温度为400℃,降解介质条件pH=7时,I-TiO2光催化活性明显优于未掺杂的TiO2。光催化降解过程通过红外光谱(IR),总有机碳(TOC)跟踪测定,比较了TiO2掺杂前后降解RhB和对氯苯酚(4-CP)的光催化特性差异;同时采用苯甲酸荧光光度法跟踪测定体系中的氧化物种,表明在可见光下,I-TiO2光催化体系中产生.OH高活性氧化物种从而氧化降解目标化合物。     

漂浮型可见光催化剂Fe-N-TiO_2/FP-CTS的制备及其对溶解性柴油的降解

以漂珠为载体,用壳聚糖对漂珠进行改性,并采用溶胶凝胶法,制备了Fe-N共掺杂改性TiO2的漂浮型可见光催化剂(Fe-N-TiO2/FP-CTS),使用X射线衍射(XRD)、紫外可见分光光谱(UV-Vis)、N2吸附-脱附(BET)和扫描电子显微镜(SEM)等分析进行表征。研究结果表明,用壳聚糖改性漂珠可以增加复合光催化剂的比表面积和孔容;相较于N-掺杂TiO2/FP复合光催化剂,Fe-N共掺杂更能促进对复合光催化剂可见光的吸收;光催化4 h后,Fe-N-TiO2/FP-CTS对溶解性柴油的降解率达到61.7%,明显优于Fe-N-TiO2/FP和N-TiO2/FP。当初始pH=5,柴油乳化剂浓度=120 mg/L时,复合光催化剂对溶解性柴油的光催化降解效果最佳。     

低密度聚乙烯膜负载型Fe/N-TiO_2制备及光催化降解二苯胺

采用溶胶凝胶法研制了Fe、N单独掺杂或Fe、N共同掺杂改性TiO_2催化剂,并用浸渍法负载于低密度聚乙烯(LDPE)膜上,制备出LDPE膜负载型催化剂。利用X射线衍射、X射线能谱、紫外—可见光吸收光谱、扫描电子显微镜对催化剂进行表征分析,并考察了催化剂种类、二苯胺(DPA)初始浓度、pH、曝气等因素对降解DPA的影响。结果表明:LDPE膜负载型Fe/N-TiO_2在可见光区有较强的吸收;负载的Fe/N-TiO_2粒子均匀地分布于LDPE膜表面;在氙灯的可见光照射下,DPA初始质量浓度为20mg/L、曝气量为2L/min、溶液pH为3时,Fe/N-TiO_2光催化反应90min时DPA降解率可达到80.11%。     

以PEG为模板剂制备Bi_2O_2CO_3及其可见光光催化性能

以聚乙二醇-6000(PEG-6000)为模板剂水热法制备碳酸氧铋(p-Bi2O2CO3)粉末,采用X射线衍射(XRD)、扫描电镜(SEM)、X射线光电子能谱(XPS)、透射电子显微镜(TEM)和紫外可见漫反射(DRS)对粉末进行了初步表征。在可见光(λ≥420 nm)照射下,以罗丹明B(RhB)和水杨酸(SA)光催化降解实验为探针反应,实验结果表明,p-Bi2O2CO3具有较高的光催化活性,对RhB和SA有较好的降解效果。通过紫外-可见光谱(UV-Vis)、红外光谱(IR)和测定总有机碳(TOC)含量,光催化反应35 h后RhB的矿化率为77%,同时对SA的降解率达到43%。同时,采用N,N-二乙基对苯二胺(DPD)分光光度法和对苯二甲酸荧光光度法分别测定了降解过程中H2O2和羟基自由基(·OH)的变化,表明p-Bi2O2CO3/Vis光催化降解机理涉及到·OH历程。     

壳聚糖/纳米CdS复合颗粒可见光光催化降解猩红B动力学研究

采用仿生矿化法制备了壳聚糖/纳米CdS复合颗粒光催化剂,并用于可见光光催化降解猩红B染料模拟废水,研究了猩红B初始浓度、pH、催化剂投加量和催化剂重复使用次数等因素对猩红B光催化降解的影响.X射线衍射(XRD)分析表明,壳聚糖能有效负载CdS纳米微晶.采用Langmuir-Hinshelwood模型描述壳聚糖/纳米CdS复合颗粒可见光光催化降解猩红B反应动力学行为,在猩红B初始质量浓度较低(≤20 mg/L)时,光催化降解过程符合假一级动力学方程.降低猩红B初始浓度和溶液pH都可显著增大光催化降解速率常数;催化剂投加量小于0.7 g/L时,光催化降解速率随其增加而增大,但催化剂投加量过大会使光催化降解速率减小;催化剂重复使用第5次时,猩红B光催化降解速率常数仍为第1次使用时的63.4%.     

碘掺杂Ti02可见光光催化性能研究

在低于100℃温度条件下，采用溶胶一凝胶法以钛酸正丁酯为钛源，碘酸钾为碘源，制备了I掺杂纳米TiO2催化剂（I-TiO2），运用x-射线衍射（XRD）、透射电镜（TEM）及x-射线光电子能谱（XPS）等对催化剂进行表征，结果表明，TiO2及I-TiO2催化剂均为锐钛矿，I吸附并包裹在TiO2表面或以间隙进入的形式存在，并未进入TiO2晶格。通过在可见光照射下（A〉420nm）以罗丹明B（RhodamineB，RhB）的光催化降解为探针反应研究了在不同条件下制备催化剂的催化性能，结果表明，掺杂比为n1：n^ti=0．05：l，焙烧温度为400℃，降解介质条件pH=7时，l-TiO2光催化活性明显优于未掺杂的TiO2。光催化降解过程通过红外光谱（IR），总有机碳（TOC）跟踪测定，比较了TiO2掺杂前后降解RhB和对氯苯酚（4-CP）的光催化特性差异；同时采用苯甲酸荧光光度法跟踪测定体系中的氧化物种，表明在可见光下，I-TiO2光催化体系中产生·OH高活性氧化物种从而氧化降解目标化合物。     

掺硫改性TiO2对活性艳红X-3B的光催化降解性能研究

以硫脲为硫的源物质,以钛酸四丁酯为TiO2的前驱体,采用溶胶-凝胶法制备了掺硫改性TiO2光催化剂.以活性艳红X-3B为目标污染物,研究了该催化剂的光催化降解性能,对硫掺杂量、催化剂焙烧温度、溶液pH值以及催化剂添加量等影响因素进行了研究,并采用XRD分析手法对光催化剂进行表征.结果表明,经掺硫改性后的TiO2的催化活性有了很大提高,且硫的掺杂有一个最佳值,即Ti:S的摩尔比为1:1.经掺硫改性的TiO2在可见光区具备一定的催化活性,180 min内对活性艳红X-3B的去除率可达35.1%,且在紫外光区的催化活性优于纯TiO2.     

负载型纳米复合半导体WO_3-TiO_2/AC光催化降解刚果红废水

采用溶胶-凝胶-浸渍-焙烧法制备了负载型纳米复合半导体WO3-TiO2/AC光催化剂,以偶氮染料刚果红为目标降解物,通过正交实验优化了刚果红废水的降解条件,并对其光催化动力学进行了探讨.结果表明,刚果红废水的最佳降解条件为:催化剂投加量10 g/L,pH=7,H2O2用量为3.5 mL/L.在最佳条件下,当刚果红废水起始浓度为40 mg/L时,反应120 min后,刚果红溶液的去除率可达95.21%,较相同条件下TiO2/AC对刚果红染料的降解率提高了19.57%.光催化剂对刚果红的光催化降解符合Langmuir-Hinshelwood(L-H)模型.     

天然沸石负载La2O3-ZnO-TiO2光催化降解活性艳红K-2BP

利用80目天然斜发沸石作载体制备La2O3(0.5%)-ZnO(20%)-TiO2/沸石复合光催化剂,以20 W紫外灯为光源,在自制的光催化反应器中降解活性艳红K-2BP,考察了光照时问、空气通入量、催化剂用最、溶液初始浓度、H2O2与Fe3 投加量等对活性艳红K-2BP光催化降解率的影响.结果表明,当溶液初始浓度为60 mg/L,催化剂投加量为12 g/L,通气量为1 200 mL/min,光照2.5 h,活性艳红K-2BP的降解率可达99.2%;H2O2和Fe3投加量为4 mL/L和3 g/L时,光照1 h活性艳红K-2BP降解率分别为100%和97.2%.紫外-可见吸收光谱显示,LZTZ光催化剂町有效降解印染废水.     

银钛共负载型光催化材料降解甲基橙废水简

以膨胀珍珠岩为载体，采用溶胶凝胶法对其进行负载，制备出不同类型的光催化材料（TiO₂-EP、Ag⁺-TiO₂-EP），并在模拟日光条件下，研究其对甲基橙溶液的降解效果。结果表明，浸渍3次且担载0.04% Ag⁺的负载型TiO₂光催化活性最高，在光催化剂用量为0.3 g，20 mL初始浓度为10 mg/L甲基橙溶液光照4 h后降解率可达81.6%，且甲基橙的光催化降解服从一级动力学方程。回收3次后仍有较强的活性，其2 h降解率为24.8%。     

汉沙黄/TiO_2光催化剂的制备及其光催化活性

采用溶剂热合成法制备了一种新型的汉沙黄/TiO2复合物光催化剂,利用多种手段SEM、XRD、FT-IR对催化剂的样品形貌、结构进行表征。分别以罗丹明B、亚甲基蓝、中性红为目标降解物,考察了可见光下溶液pH值对催化剂的吸附性能和催化活性的影响。结果表明,敏化后的TiO2对光的响应由紫外区扩展到可见区,催化活性优于纯TiO2,对上述3种染料的吸附率分别为19.2%、29.2%和43.2%,降解率分别为98.6%、92.5%和97.8%。制备的汉沙黄/TiO2光催化剂稳定性好,重复使用率高,在印染废水处理中具有很好的应用前景。     

CdS-TiO_2/MWCNTs结构表征及其光催化性能

采用溶胶-凝胶法,制备了多壁碳纳米管(MWCNTs)负载的双组分复合半导体光催化剂CdS-TiO2/MWCNTs。通过透射电镜(TEM)、比表面分析(BET)、X射线衍射(XRD)和紫外-可见吸收光谱(UV-vis)等分析方法对光催化剂进行了结构表征,并考察了CdS-TiO2/MWCNTs对甲苯降解的光催化性能。结果表明:纳米活性粒子CdS-TiO2均匀负载于MWCNTs上,比表面积、光吸收阈值和强度增大,活性粒子间以及活性粒子与载体之间具有协同作用,有利于光催化性能的提高,CdS-TiO2/MWCNTs在主波长为254 nm紫外光照射下对甲苯的降解效果较好,去除率可达55.3%。     

CuO/TiO2-H2O2可见光催化亚甲基蓝脱色效果及影响因素研究

以水解法制备的锐钛矿型TiO2为载体,制备了CuO/TiO2型光催化剂.以亚甲基蓝为对象,在可见光照射下研究了H2O3加入量、pH值和催化剂投加量对脱色效果的影响,同时与改性前的TiO2催化剂进行了脱色效果的对比.结果表明亚甲基蓝在碱性条件下能较好脱色,H2O2用量和CuO/TiO2催化剂投加量分别为每1 000 mL反应液各加入10 mL和0.1 g时脱色最好;另外,TiO2催化剂也在碱性条件下能较好脱色,H2O2用量和催化剂投加量分别为每1 000 mL反应液各加入12.5 mL和0.1 g时脱色最好.最优条件下对比实验表明,CuO/TiO2型催化剂在可见光照射下具有很高的催化活性,亚甲基蓝2 h脱色率达到88%,远好于改性前的TiO2和Degussa P25催化剂.     

Preparation,characterization, and photocatalytic activity evaluation of Fe–N-codoped TiO2/fly ash cenospheres floating photocatalyst

Nitrogen-doped titanium dioxide (TiO₂) and Fe–N-codoped TiO₂ layers on fly ash cenospheres (FAC) as floating photocatalyst were successfully prepared through sol–gel method. Photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), ultraviolet (UV)–Vis diffuse reflectance spectroscopy (DRS), and nitrogen adsorption analyses for Brunauer–Emmett–Teller (BET) specific surface area. Photocatalytic efficiency of the prepared catalyst was evaluated through using the decomposition of Rhodamine B (RhB) as a model compound under visible light irradiation. Photocatalytic activity and kinetics of catalyst under visible light were detected in details from different Fe/Ti mole ratios by detecting photodegradation of RhB. Experimental results show that when the calcination temperature was 550 °C, the dosage of FAC was 3.0 g, and the mole ratio of Fe/Ti was 0.71 %; the synthesized Fe–N-TiO₂/FAC photocatalyst presented as anatase phase and that N and Fe ions were doped into TiO₂ lattice. The material’s specific surface area was 34.027 m²/g, and UV–Vis diffuse reflectance spectroscopy shows that the edge of the photon absorption has been red shifted up to 400–500 nm. Fe–N-codoped titanium dioxide on FAC had excellent photocatalytic activity during the process of photodegradation of RhB under visible light irradiation.

     

H4SiW12O40/TiO2/beads光催化降解亚甲基蓝的研究

以钛酸四丁酯为原料，空心微珠为载体，采用溶胶凝胶法制备TiO₂/beads光催化剂载体，然后浸渍法制备出H₄SiW₁₂O₄₀/TiO₂/beads表面负载修饰型复合光催化剂，并运用SEM、XRD、FT-IR和DRS对催化剂进行表征和分析。研究了H₄SiW₁₂O₄₀/TiO₂/beads对亚甲基蓝降解的光催化活性，考察了光强度、pH值、曝气量、底物浓度和催化剂用量等对催化效率的影响。实验结果表明，在中性条件下，H₄SiW₁₂O₄₀/TiO₂/beads催化剂的投加量为0.25 g/L，浓度为7.5 mg/L的亚甲基蓝溶液在250 W的紫外灯和600 W的可见光灯下光照60 min降解率分别可达到94.5%和55%。     

天然沸石负载La2O3-ZnO-TiO2光催化降解活性艳红K-2BP

利用80目天然斜发沸石作载体制备La₂O₃(0.5%)-ZnO(20%)-TiO₂/沸石复合光催化剂，以20 W紫外灯为光源，在自制的光催化反应器中降解活性艳红K-2BP，考察了光照时间、空气通入量、催化剂用量、溶液初始浓度、H₂O₂与Fe³⁺投加量等对活性艳红K-2BP光催化降解率的影响。结果表明，当溶液初始浓度为60 mg/L，催化剂投加量为12 g/L，通气量为1 200 mL/min，光照2.5 h，活性艳红K-2BP的降解率可达99.2%；H₂O₂和Fe³⁺投加量为4 mL/L和3 g/L时，光照1 h活性艳红K-2BP降解率分别为100%和97.2%。紫外可见吸收光谱显示，LZTZ光催化剂可有效降解印染废水。     

纳米TiO2/活性炭复合光催化剂的制备及其对甲醛气体降解

研究了纳米TiO2/活性炭复合光催化剂对空气中典型污染气体甲醛的光催化降解特性。采用扫描电镜(SEM)表征复合催化剂的表面特征。结果显示,经改性后的纳米TiO2在复合催化剂表面分布均匀,呈球状。对甲醛气体的降解实验显示TiO2负载量为1%时对甲醛的去除效果最好,6 h去除率为61.7%。结果显示复合催化剂把甲醛气体分解成CO2,可以直接排空,无二次污染。     

Photodegradation of perfluorooctanoic acid by synthesized TiO2-MWCNT composites under 365nm UV irradiation

Degradation of perfluorooctanoic acid (PFOA) is of great importance due to its global distribution, persistence and toxicity to bioorganisms. In present study, a composite TiO₂ with multiple wall carbon nano-tubes (MWCNTs) was synthesized using sol-gel method and it was used as photocatalyst to degrade PFOA in water. The prepared composite catalyst displayed significant absorption in UV to visible light region. The loading content of TiO₂ on MWCNTs could be adjusted by changing the ratio of precursor to MWCNTs. Due to the combined effect of the adsorption ability and e⁻ transport capacity of MWCNT, the composites displayed much higher photocatalytic ability to PFOA as compared to pure TiO₂ under UV irradiation. The photocatalyst prepared with 10:1 of tetrabutyl titanate/MWCNT was the most effective. With the optimal dosage at 1.6 g L⁻¹, almost 100% of PFOA was degraded in acid medium after irradiation for 8 h. It was proposed that PFOA were mainly degraded by stepwise losing a moiety of CF₂.     

High-performance for hydrogen evolution and pollutant degradation of reduced graphene oxide/two-phase g-C<Subscript>3</Subscript>N<Subscript>4</Subscript> heterojunction photocatalysts

We have successfully synthesized the composites of two-phase g-C₃N₄ heterojunction photocatalysts by one-step method. And the reduced graphene oxide/two-phase g-C₃N₄ heterojunction photocatalyst was fabricated via a facile hydrothermal reduction method. The characterization results indicated that the two-phase g-C₃N₄ was integrated closely, and the common phenomenon of agglomeration for g-C₃N₄ was significantly reduced. Moreover, the oxidized graphene was reduced successfully in the composites and the graphene was overlaid on the surface or the interlayers of g-C₃N₄ heterojunction composite uniformly. In addition, we have carried out the photocatalytic activity experiments by H₂ evolution and rhodamine B removal, tetracycline removal under the visible light irradiation. The results revealed that the composite has improved the separation efficiency a lot than the pure photocatalyst. The photocurrent test demonstrated that the recombination of electrons and holes were efficiently inhibited as well as enhanced the photocatalytic activity. The 0.4% rGO loaded samples, 0.4% rGOCN2, own the best performance. Its rate of H₂ evolution was 15 times as high as that of the pure g-C₃N₄.